Improvement in machines for dressing millstones



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` .Letters .Patent No. 102,968, dated I.May l0, 1870, i e

` IMPRovnMeNT IN Macular-.stron DRESSING M ILLs'roNns.

yThe Schedule referred to inthese Letters Patent and making part o! the same.

` Toall whom it may concern.-

Be itvknown that we, vWILLIAM Pickens'and PE- TER DALRYMPLPnof Chicago,1inthe countyl of Cook and VState ot Illinois,

the following is'a"y full, clear, and exactdescription thereorwhich will enablethose skilled inthe art to make and use the same, reference being had to the accompanying drawings and letters marked thereon `making a part of this specification, in which- Figure 1 is a perspective representation ofour invention. l

',Iiigure 2, a vertical sectional elevation of the same, looking'in the direction indicated by dartw.

Figure 3, an 'elevation of apart appertaining thereto, detached fromthe other parts.

The nature ofi` the `present invention consists of a substantial frame, whichV restsupon the faceof a millstone., and centers upon the top ot' the spindle ofthe bed-stone or inthe bale of the runner, and which `is"` --pi'ovided with an `automatic feed-arm, which is oper- (ated upon bya'screw-rod, and spacesthe distance which the cracks or` groovesin the stones are to have fromeach other as `the whole, togethenwith the details of the machine, is hereinafter fully specified.

I A B represents a substantial semicircular frame, I which is made o f cast-iron, and of such size as to have a suitablebearing on a millstone.

To the .central part oi`- this frame, and near theV straight part I, is"`attached` a hub,"0, whichfsupports an adjustable centre piece or pivot, D, the lower end of which has a step formed in it, to bear on the top of the spiudlefwhen a bed-stoneis beingdressed, and

- which is to be inverted so that its top endmay bear inthe step vof the bale of the runner when the latter is being dressed; ,a set-screw, E, being tapped into said hn'b, holds the pivot D in place when adj usted,

That part oft-he frame shown at I is provided with a guidetraok, I I), in `orderthat a head-block, O, may readily move back and .forth thereon. -This headblock O `supports and carries an arm, G, which is also provided with a track, S, S,in order that thev` gauge` head It may be readilymoved back and forth on said arm when the cracks in the stone are Vbeing made.

In order to give the arm G an automatic feed Amotion whichwilhso move the diamond-pointeV on the.

stone as to make the cracks the proper-"distance from each other, I use the Vfollowing devices; A- screw-rod, J, is placed infront of Vthat part ot vthe fm'mehown at I, and has bearings in each of its ends'h; and on have l'invented a` Machine .for Dressing Millstones;` and `we do herebydeclare that the two ends of this rod are securely fastened ratchetwheels l, which are turned by means of pawls m,'fig. 1. These pawlsare pivoted to arms U, which are port a rod,-H, which is operated as follows: a connecting-rod, L, is jointed to said rod H, and to a vertical lever, M, which is pivotedto the arm G, at N. The lower end of lever M is pivoted to a horizontal against whichthe gauge-head R strikes 'when making a crack, and carries said bar toward the end of arm Gr, and consequently so turns the lever M on its pivot N as to cause the connecting-rod L to move the arms U. Bymeans of this movement, the pawls in m turn the ratchet-wheels l one notch, and turn the screw-rod J i in a nut,-K, fig. 2, fastened to block-head O, and consequently moves forward the arm G attached to said erned by the pitch of thread on the screw-rod J. It is well, however-,here to state that the arm G should move about ouetwentyltilth.of an inch atleaeh cut of the diamond-.point (1,. this being the distance that the cracks in the stone are usually made apart.

VIn order to lillV the space between the ends of that part of the frame I and lthe ratchets Z, and to preve'nt the' arms U from moving back too tar, looped arms, V, are pivoted to the said arms U, and their looped parts-pass around the endsof the screw-rod J, the slots in .the loop being just long enough to allow the armsffU to move the required distance. YVhen it is required to remove the gauge-head from the guides S S, the pin T, on the rod Y, canberaised up into a notch, d, tig. 2, made in the arm G.

Havir g thus described our invention, ,What we claim, and desire. to secure by Letters Patent, is-,V

1. The arm G, provided with a traversingheadblock O, track S S, gauge-head R, -and point a, cornbined with the screw-rod J, operated by the ratchets Z, pawls on., arms U, rod H, connecting-rod L Y, andlever lt A' 2. The adjustable and reversible center D, cou1- bined with the frame I AB, hub 0, and arm G of a stone-dressing machine.

' WILLIAM PICKENS.

PETER DALRYMPLE.

Witnesses:

E. E. GIBSON,

. Gr.l S. CHAPIN.

pivoted to the circular part A of the frame, and supbar,-Y, which has a projecting pin, T, figs. 1 and 2,

head, the distance which the arm moves being gov- A 

